Council of Ephesus 431

                                                              i.      Battle against heresy of Nestorianism, attributed to Nestorius of Antioch, patriarch of Constantinople: the claim that Mary was not Mother of God only of Jesus Christ, thus, giving her a title of Kristotokos (Christ bearer).  She was only mother of his human nature.  This called into question the unity of the person of Jesus Christ having two natures: divine and human.  Nestorius proclaimed two persons because there were two natures, human and divine.  Cyril of Alexandria defended the teaching of one person and two natures.  “It was not that an ordinary man was born first of the holy Virign, on whom afterwards the WORD descended; what we say is that, being united with the flesh from the womb, the WORD has undergone birth in the flesh, making the birth in the flesh his own, thus, the holy Fathers have unhesitatingly called the holy Virgin “Mother of God” theotokos.” Cyril of Alexandria 430/1